Grouping based on date difference results..

I have found date difference between two dates. Then i try to group the date difference using measure based dimension like 0 to1 day, 2 to 3 days and above 3 days given measure as the date difference.Then using that dimension i have created each group using aggregation in calculated measure. But all the values coming under above 3 days group. But lots of value o to 3 days. Nothing is showing in that group. I can't find out the issue.